Hi everybody! New here, not sure whether this is the right place to put this. I'm looking for a part...
I have a dysfunctional Delta Lab Super Time Line ADM2048 delay processor on my desk. The problem is its internal backup battery (a red cylinder with axial leads) has failed. I've looked up the part number (SAFT P/N# M0703 4483) with no luck. I'm wondering if anybody here can help.
Note: After I removed the battery and cleaned the unit a bit I powered it up and measured about 5V across the terminals where the battery used to be. If I can't find an exact part would it be possible to purchase a 5V rechargeable back-up battery, PCB-mount, and replace the old battery with that?
I have a dysfunctional Delta Lab Super Time Line ADM2048 delay processor on my desk. The problem is its internal backup battery (a red cylinder with axial leads) has failed. I've looked up the part number (SAFT P/N# M0703 4483) with no luck. I'm wondering if anybody here can help.
Note: After I removed the battery and cleaned the unit a bit I powered it up and measured about 5V across the terminals where the battery used to be. If I can't find an exact part would it be possible to purchase a 5V rechargeable back-up battery, PCB-mount, and replace the old battery with that?
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It is a 3.6v nicad battery There will be a 5v charging voltage there when the unit is powered, but it comes through a 510 ohm R183. Make sure D60 has not shorted.
Your battery or one before it has leaked battery spooge, and has corroded some nearby parts. I have had some success cleaning that off with warm water and CLR, a cleaning product at the grocery or hardware store. CLR is for removing rust and mineral stains from sinks and such.
Your battery or one before it has leaked battery spooge, and has corroded some nearby parts. I have had some success cleaning that off with warm water and CLR, a cleaning product at the grocery or hardware store. CLR is for removing rust and mineral stains from sinks and such.
I would fit a 3.6v NIMH battery. Something as big as Lithium battery ER14505/TC 2400mAh 3,6V ULTRALIFE AA | eBay is a bit of an overkill but VARTA 55615603059 BATTERY MEMPAC PCB NIMH 3CELL 3.6V 150mAH 150H RECHARGEABLE | eBay would be ideal
Do NOT use a lithium, the charger is probably crude and could cause a fire.
NiCd batteries tolerated simple chargers better than other types. A NiMH should be OK
Exactly. Two 1N14148 silicon diodes in series with a 1k resistor does a better job of fast charge and then trickling
The circuit does a little more than charge. From the general +5 there is a diode for isolation, and the new voltage powers RAM while it also charges the battery. At power off, the battery keeps the RAM alive, while the diode blocks the battery from trying to power the entire unit.
SO any alteration has to keep that goal in mind too.
In image below, battery is lower left corner, and D59,60 come right off the output of an unseen 7805.
SO any alteration has to keep that goal in mind too.
In image below, battery is lower left corner, and D59,60 come right off the output of an unseen 7805.
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If the 7805 Common goes directly to 0V, then +5A is actually more like +4.4V and the battery is trickling at 2mA, a bit high for a NiMH.
Putting a second diode in series with D60 would have negligible effect on +5B and reduce the trickle to 1mA
Putting a second diode in series with D60 would have negligible effect on +5B and reduce the trickle to 1mA
The CMOS RAM only needs like 2.5v to keep memory anyway.
My crummy chopped up scan exactly crops out the center legs of the Vregs, but I can see just the edge of a diode in the ground leg of the fourth regulator down, the 7805. So it appears they compensated.
My crummy chopped up scan exactly crops out the center legs of the Vregs, but I can see just the edge of a diode in the ground leg of the fourth regulator down, the 7805. So it appears they compensated.
Im glad I found this thread. I have this unit with the same problem.
I found NiMH 3.6V 80mAh batteries on ebay. I think they should work. The max trickle current for NiMH is around 1/50th of the mAh.
So that should be around 1.6mA for this battery. This unit continuously charges the battery so trickle current should not go above 1.6mA.
Calculations for this unit:
Vcc = 5V,
Vbat = 3.6V when battery is full
Vd = .7V diode drop
So the voltage across the 510 Ohm resistor is:
Vcc – Vbat – Vd => 5 – 3.6 - .7 = .7Volts
That means the current through the resistor is:
I = V/R => .7 / 510 = 1.4mA
So the trickle current provided by this unit will be 1.4mA when the battery is full. Since max trickle for the battery is about 1.6mA this should be perfect for this.
I think my calculations are correct. If my calculations are wrong let me know.
Thanks,
Pete
I found NiMH 3.6V 80mAh batteries on ebay. I think they should work. The max trickle current for NiMH is around 1/50th of the mAh.
So that should be around 1.6mA for this battery. This unit continuously charges the battery so trickle current should not go above 1.6mA.
Calculations for this unit:
Vcc = 5V,
Vbat = 3.6V when battery is full
Vd = .7V diode drop
So the voltage across the 510 Ohm resistor is:
Vcc – Vbat – Vd => 5 – 3.6 - .7 = .7Volts
That means the current through the resistor is:
I = V/R => .7 / 510 = 1.4mA
So the trickle current provided by this unit will be 1.4mA when the battery is full. Since max trickle for the battery is about 1.6mA this should be perfect for this.
I think my calculations are correct. If my calculations are wrong let me know.
Thanks,
Pete
> NiMH 3.6V 80mAh batteries
Interesting. But the original part is surely a NiCad. While these have fallen out of favor, they ARE still available. Most notably, solar yard lights for cold climates (in Maine winter nights, NiMH craps out and NiCad keeps going). Also as replacements for millions of PCs and similar logic contraptions. Google finds a million hits for "nicad battery 3.6V"
3.6V NiCd Battery Packs
https://www.newark.com/c/batteries-chargers/batteries-rechargeable?battery-voltage=3.6v
https://www.homedepot.com/p/Power-G...hone-Battery-3-6V-700mAh-NiMH-76154/203828087
Interesting. But the original part is surely a NiCad. While these have fallen out of favor, they ARE still available. Most notably, solar yard lights for cold climates (in Maine winter nights, NiMH craps out and NiCad keeps going). Also as replacements for millions of PCs and similar logic contraptions. Google finds a million hits for "nicad battery 3.6V"
3.6V NiCd Battery Packs
https://www.newark.com/c/batteries-chargers/batteries-rechargeable?battery-voltage=3.6v
https://www.homedepot.com/p/Power-G...hone-Battery-3-6V-700mAh-NiMH-76154/203828087
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Thanks. I looked into NiCad's a bit but the capacity of those was larger. I couldn't find anything under 600mAh. I was worried about the charge current in the unit is low (only about 2ma) so anything with larger capacity will take forever to charge.
They assumed the unit would be on long periods, like all day. The drain on the battery is tiny, so it isn't like they needed to recharge the battery from flot zero. Once it is fully charged, even if it takes all day, it should stay that way as the draw from it while power is off is so small.